Teknochild
Don't take this the wrong way.
But you really don't know much about how a motor works do you???

A motor canot run without vacuum.
At idle any car, and the 335 runs at about 18 inch of vacuum.
Thats more then enogh to open the valve.
The car will always run under vacuum until you creat enough load to build boost.

See this video i did back in December.
Notice the vacuum my car has will driving.
Then I push in the clutch and rev it out to hear the HKS BOV.
0 boost is at the 11:30 positin on the gauge. And 20 inch of vacuum at 9:00.

Just go pop the hood on you 335, undo the return tube from the diverter valve and see for yourself instead of saying thing you don't know.

you seem to be confusing idle with, driving along with no throttle.... nowhere in that video are you at idle, you have vacuum because the engine is spinning with the throttle body closed (you took your foot off the gas)

dont put words in my mouth, i never said an engine doesnt develop vacuum, i said at idle there is most likely none, and by that i meant there is not less pressure on one side of the spring then the other, and if there is it would not be enough to lift it no matter how light it was

idle = open throttle body = close to equal vacuum on both sides of the spring, no lift

getting off throttle = vacuum on manifold side = ifted spring = diverter open = doesnt matter because there is positive pressure

once the throttle body is opened (idle) it does not matter if vacuum is created, it will not effect anything since it will be present on both sides of the spring, and if the throttle body is closed and the vacuum is presentm sur ethe spring will lift like normal, but its not going to suck air in on the exit line, because the vacuum isnt on that side of the throttle body